nesemu/cpu/op.h

#include "../include/cpu.h"

#ifndef CPU_OP_H
#define CPU_OP_H

// The number associated with each op code is the matching line of the ALU op code.
// Based on the table here: https://www.nesdev.org/wiki/CPU_unofficial_opcodes
enum op_code_base {
    OP_CODE_BASE_ORA = 0x00,
    OP_CODE_BASE_AND = 0x20,
    OP_CODE_BASE_EOR = 0x40,
    OP_CODE_BASE_ADC = 0x60,
    OP_CODE_BASE_STA = 0x80,
    OP_CODE_BASE_LDA = 0xa0,
    OP_CODE_BASE_CMP = 0xc0,
    OP_CODE_BASE_SBC = 0xe0
};

typedef enum {
    ADDR_MODE_ABSOLUTE,             // a
    ADDR_MODE_ABSOLUTE_JUMP,        // (a)
    ADDR_MODE_ABSOLUTE_INDEXED_X,   // a,x
    ADDR_MODE_ABSOLUTE_INDEXED_Y,   // a,y
    ADDR_MODE_ACCUMULATOR,          // A
    ADDR_MODE_IMMEDIATE,            // #i
    ADDR_MODE_IMPLICIT,             // Imp
    ADDR_MODE_INDIRECT_X,     // (d,x)
    ADDR_MODE_INDIRECT_JUMP,        //
    ADDR_MODE_INDIRECT_Y,     // (d),y
    ADDR_MODE_RELATIVE,             // label
    ADDR_MODE_ZERO_PAGE,            // d
    ADDR_MODE_ZERO_PAGE_INDEXED_X,  // d,x
    ADDR_MODE_ZERO_PAGE_INDEXED_Y,  // d,y
} AddressingMode;

void process_op_code(byte op);

#endif